Just started first PC build. Screwed in Antec 550 TruePower to case, connected case fan to standard 4 pin peripheral outlet on psu (not fan only outlet), plugged in the psu and turned it on (black switch from 0 to 1). I noticed that the case fan is not running. Then I noticed that neither of the 2 fans built into the psu are running.

Does this automatically mean that the psu is DOA? Is it possible that simply screwing the psu into the case has created a short. Does the motherboard need to be connected to the psu for the psu's internal fans to be running? What is the easiest way to test if the psu is DOA?